//     Underscore.js 1.8.2
//     http://underscorejs.org
//     (c) 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
//     Underscore may be freely distributed under the MIT license.
(function () {
  // Baseline setup
  // --------------
  // Establish the root object, `window` in the browser, or `exports` on the server.
  //   var root = this;
  //   // Save the previous value of the `_` variable.
  //   var previousUnderscore = root._;
  // Save bytes in the minified (but not gzipped) version:
  var ArrayProto = Array.prototype,
      ObjProto = Object.prototype,
      FuncProto = Function.prototype; // Create quick reference variables for speed access to core prototypes.

  var push = ArrayProto.push,
      slice = ArrayProto.slice,
      toString = ObjProto.toString,
      hasOwnProperty = ObjProto.hasOwnProperty; // All **ECMAScript 5** native function implementations that we hope to use
  // are declared here.

  var nativeIsArray = Array.isArray,
      nativeKeys = Object.keys,
      nativeBind = FuncProto.bind,
      nativeCreate = Object.create; // Naked function reference for surrogate-prototype-swapping.

  var Ctor = function () {}; // Create a safe reference to the Underscore object for use below.


  var _ = function (obj) {
    if (obj instanceof _) return obj;
    if (!(this instanceof _)) return new _(obj);
    this._wrapped = obj;
  }; // Export the Underscore object for **Node.js**, with
  // backwards-compatibility for the old `require()` API. If we're in
  // the browser, add `_` as a global object.
  //   if (typeof exports !== 'undefined') {
  //     if (typeof module !== 'undefined' && module.exports) {
  //       exports = module.exports = _;
  //     }
  //     exports._ = _;
  //   } else {
  //     root._ = _;
  //   }


  module.exports = _; // Current version.

  _.VERSION = '1.8.2'; // Internal function that returns an efficient (for current engines) version
  // of the passed-in callback, to be repeatedly applied in other Underscore
  // functions.

  var optimizeCb = function (func, context, argCount) {
    if (context === void 0) return func;

    switch (argCount == null ? 3 : argCount) {
      case 1:
        return function (value) {
          return func.call(context, value);
        };

      case 2:
        return function (value, other) {
          return func.call(context, value, other);
        };

      case 3:
        return function (value, index, collection) {
          return func.call(context, value, index, collection);
        };

      case 4:
        return function (accumulator, value, index, collection) {
          return func.call(context, accumulator, value, index, collection);
        };
    }

    return function () {
      return func.apply(context, arguments);
    };
  }; // A mostly-internal function to generate callbacks that can be applied
  // to each element in a collection, returning the desired result 鈥� either
  // identity, an arbitrary callback, a property matcher, or a property accessor.


  var cb = function (value, context, argCount) {
    if (value == null) return _.identity;
    if (_.isFunction(value)) return optimizeCb(value, context, argCount);
    if (_.isObject(value)) return _.matcher(value);
    return _.property(value);
  };

  _.iteratee = function (value, context) {
    return cb(value, context, Infinity);
  }; // An internal function for creating assigner functions.


  var createAssigner = function (keysFunc, undefinedOnly) {
    return function (obj) {
      var length = arguments.length;
      if (length < 2 || obj == null) return obj;

      for (var index = 1; index < length; index++) {
        var source = arguments[index],
            keys = keysFunc(source),
            l = keys.length;

        for (var i = 0; i < l; i++) {
          var key = keys[i];
          if (!undefinedOnly || obj[key] === void 0) obj[key] = source[key];
        }
      }

      return obj;
    };
  }; // An internal function for creating a new object that inherits from another.


  var baseCreate = function (prototype) {
    if (!_.isObject(prototype)) return {};
    if (nativeCreate) return nativeCreate(prototype);
    Ctor.prototype = prototype;
    var result = new Ctor();
    Ctor.prototype = null;
    return result;
  }; // Helper for collection methods to determine whether a collection
  // should be iterated as an array or as an object
  // Related: http://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength


  var MAX_ARRAY_INDEX = Math.pow(2, 53) - 1;

  var isArrayLike = function (collection) {
    var length = collection != null && collection.length;
    return typeof length == 'number' && length >= 0 && length <= MAX_ARRAY_INDEX;
  }; // Collection Functions
  // --------------------
  // The cornerstone, an `each` implementation, aka `forEach`.
  // Handles raw objects in addition to array-likes. Treats all
  // sparse array-likes as if they were dense.


  _.each = _.forEach = function (obj, iteratee, context) {
    iteratee = optimizeCb(iteratee, context);
    var i, length;

    if (isArrayLike(obj)) {
      for (i = 0, length = obj.length; i < length; i++) {
        iteratee(obj[i], i, obj);
      }
    } else {
      var keys = _.keys(obj);

      for (i = 0, length = keys.length; i < length; i++) {
        iteratee(obj[keys[i]], keys[i], obj);
      }
    }

    return obj;
  }; // Return the results of applying the iteratee to each element.


  _.map = _.collect = function (obj, iteratee, context) {
    iteratee = cb(iteratee, context);

    var keys = !isArrayLike(obj) && _.keys(obj),
        length = (keys || obj).length,
        results = Array(length);

    for (var index = 0; index < length; index++) {
      var currentKey = keys ? keys[index] : index;
      results[index] = iteratee(obj[currentKey], currentKey, obj);
    }

    return results;
  }; // Create a reducing function iterating left or right.


  function createReduce(dir) {
    // Optimized iterator function as using arguments.length
    // in the main function will deoptimize the, see #1991.
    function iterator(obj, iteratee, memo, keys, index, length) {
      for (; index >= 0 && index < length; index += dir) {
        var currentKey = keys ? keys[index] : index;
        memo = iteratee(memo, obj[currentKey], currentKey, obj);
      }

      return memo;
    }

    return function (obj, iteratee, memo, context) {
      iteratee = optimizeCb(iteratee, context, 4);

      var keys = !isArrayLike(obj) && _.keys(obj),
          length = (keys || obj).length,
          index = dir > 0 ? 0 : length - 1; // Determine the initial value if none is provided.


      if (arguments.length < 3) {
        memo = obj[keys ? keys[index] : index];
        index += dir;
      }

      return iterator(obj, iteratee, memo, keys, index, length);
    };
  } // **Reduce** builds up a single result from a list of values, aka `inject`,
  // or `foldl`.


  _.reduce = _.foldl = _.inject = createReduce(1); // The right-associative version of reduce, also known as `foldr`.

  _.reduceRight = _.foldr = createReduce(-1); // Return the first value which passes a truth test. Aliased as `detect`.

  _.find = _.detect = function (obj, predicate, context) {
    var key;

    if (isArrayLike(obj)) {
      key = _.findIndex(obj, predicate, context);
    } else {
      key = _.findKey(obj, predicate, context);
    }

    if (key !== void 0 && key !== -1) return obj[key];
  }; // Return all the elements that pass a truth test.
  // Aliased as `select`.


  _.filter = _.select = function (obj, predicate, context) {
    var results = [];
    predicate = cb(predicate, context);

    _.each(obj, function (value, index, list) {
      if (predicate(value, index, list)) results.push(value);
    });

    return results;
  }; // Return all the elements for which a truth test fails.


  _.reject = function (obj, predicate, context) {
    return _.filter(obj, _.negate(cb(predicate)), context);
  }; // Determine whether all of the elements match a truth test.
  // Aliased as `all`.


  _.every = _.all = function (obj, predicate, context) {
    predicate = cb(predicate, context);

    var keys = !isArrayLike(obj) && _.keys(obj),
        length = (keys || obj).length;

    for (var index = 0; index < length; index++) {
      var currentKey = keys ? keys[index] : index;
      if (!predicate(obj[currentKey], currentKey, obj)) return false;
    }

    return true;
  }; // Determine if at least one element in the object matches a truth test.
  // Aliased as `any`.


  _.some = _.any = function (obj, predicate, context) {
    predicate = cb(predicate, context);

    var keys = !isArrayLike(obj) && _.keys(obj),
        length = (keys || obj).length;

    for (var index = 0; index < length; index++) {
      var currentKey = keys ? keys[index] : index;
      if (predicate(obj[currentKey], currentKey, obj)) return true;
    }

    return false;
  }; // Determine if the array or object contains a given value (using `===`).
  // Aliased as `includes` and `include`.


  _.contains = _.includes = _.include = function (obj, target, fromIndex) {
    if (!isArrayLike(obj)) obj = _.values(obj);
    return _.indexOf(obj, target, typeof fromIndex == 'number' && fromIndex) >= 0;
  }; // Invoke a method (with arguments) on every item in a collection.


  _.invoke = function (obj, method) {
    var args = slice.call(arguments, 2);

    var isFunc = _.isFunction(method);

    return _.map(obj, function (value) {
      var func = isFunc ? method : value[method];
      return func == null ? func : func.apply(value, args);
    });
  }; // Convenience version of a common use case of `map`: fetching a property.


  _.pluck = function (obj, key) {
    return _.map(obj, _.property(key));
  }; // Convenience version of a common use case of `filter`: selecting only objects
  // containing specific `key:value` pairs.


  _.where = function (obj, attrs) {
    return _.filter(obj, _.matcher(attrs));
  }; // Convenience version of a common use case of `find`: getting the first object
  // containing specific `key:value` pairs.


  _.findWhere = function (obj, attrs) {
    return _.find(obj, _.matcher(attrs));
  }; // Return the maximum element (or element-based computation).


  _.max = function (obj, iteratee, context) {
    var result = -Infinity,
        lastComputed = -Infinity,
        value,
        computed;

    if (iteratee == null && obj != null) {
      obj = isArrayLike(obj) ? obj : _.values(obj);

      for (var i = 0, length = obj.length; i < length; i++) {
        value = obj[i];

        if (value > result) {
          result = value;
        }
      }
    } else {
      iteratee = cb(iteratee, context);

      _.each(obj, function (value, index, list) {
        computed = iteratee(value, index, list);

        if (computed > lastComputed || computed === -Infinity && result === -Infinity) {
          result = value;
          lastComputed = computed;
        }
      });
    }

    return result;
  }; // Return the minimum element (or element-based computation).


  _.min = function (obj, iteratee, context) {
    var result = Infinity,
        lastComputed = Infinity,
        value,
        computed;

    if (iteratee == null && obj != null) {
      obj = isArrayLike(obj) ? obj : _.values(obj);

      for (var i = 0, length = obj.length; i < length; i++) {
        value = obj[i];

        if (value < result) {
          result = value;
        }
      }
    } else {
      iteratee = cb(iteratee, context);

      _.each(obj, function (value, index, list) {
        computed = iteratee(value, index, list);

        if (computed < lastComputed || computed === Infinity && result === Infinity) {
          result = value;
          lastComputed = computed;
        }
      });
    }

    return result;
  }; // Shuffle a collection, using the modern version of the
  // [Fisher-Yates shuffle](http://en.wikipedia.org/wiki/Fisher鈥揧ates_shuffle).


  _.shuffle = function (obj) {
    var set = isArrayLike(obj) ? obj : _.values(obj);
    var length = set.length;
    var shuffled = Array(length);

    for (var index = 0, rand; index < length; index++) {
      rand = _.random(0, index);
      if (rand !== index) shuffled[index] = shuffled[rand];
      shuffled[rand] = set[index];
    }

    return shuffled;
  }; // Sample **n** random values from a collection.
  // If **n** is not specified, returns a single random element.
  // The internal `guard` argument allows it to work with `map`.


  _.sample = function (obj, n, guard) {
    if (n == null || guard) {
      if (!isArrayLike(obj)) obj = _.values(obj);
      return obj[_.random(obj.length - 1)];
    }

    return _.shuffle(obj).slice(0, Math.max(0, n));
  }; // Sort the object's values by a criterion produced by an iteratee.


  _.sortBy = function (obj, iteratee, context) {
    iteratee = cb(iteratee, context);
    return _.pluck(_.map(obj, function (value, index, list) {
      return {
        value: value,
        index: index,
        criteria: iteratee(value, index, list)
      };
    }).sort(function (left, right) {
      var a = left.criteria;
      var b = right.criteria;

      if (a !== b) {
        if (a > b || a === void 0) return 1;
        if (a < b || b === void 0) return -1;
      }

      return left.index - right.index;
    }), 'value');
  }; // An internal function used for aggregate "group by" operations.


  var group = function (behavior) {
    return function (obj, iteratee, context) {
      var result = {};
      iteratee = cb(iteratee, context);

      _.each(obj, function (value, index) {
        var key = iteratee(value, index, obj);
        behavior(result, value, key);
      });

      return result;
    };
  }; // Groups the object's values by a criterion. Pass either a string attribute
  // to group by, or a function that returns the criterion.


  _.groupBy = group(function (result, value, key) {
    if (_.has(result, key)) result[key].push(value);else result[key] = [value];
  }); // Indexes the object's values by a criterion, similar to `groupBy`, but for
  // when you know that your index values will be unique.

  _.indexBy = group(function (result, value, key) {
    result[key] = value;
  }); // Counts instances of an object that group by a certain criterion. Pass
  // either a string attribute to count by, or a function that returns the
  // criterion.

  _.countBy = group(function (result, value, key) {
    if (_.has(result, key)) result[key]++;else result[key] = 1;
  }); // Safely create a real, live array from anything iterable.

  _.toArray = function (obj) {
    if (!obj) return [];
    if (_.isArray(obj)) return slice.call(obj);
    if (isArrayLike(obj)) return _.map(obj, _.identity);
    return _.values(obj);
  }; // Return the number of elements in an object.


  _.size = function (obj) {
    if (obj == null) return 0;
    return isArrayLike(obj) ? obj.length : _.keys(obj).length;
  }; // Split a collection into two arrays: one whose elements all satisfy the given
  // predicate, and one whose elements all do not satisfy the predicate.


  _.partition = function (obj, predicate, context) {
    predicate = cb(predicate, context);
    var pass = [],
        fail = [];

    _.each(obj, function (value, key, obj) {
      (predicate(value, key, obj) ? pass : fail).push(value);
    });

    return [pass, fail];
  }; // Array Functions
  // ---------------
  // Get the first element of an array. Passing **n** will return the first N
  // values in the array. Aliased as `head` and `take`. The **guard** check
  // allows it to work with `_.map`.


  _.first = _.head = _.take = function (array, n, guard) {
    if (array == null) return void 0;
    if (n == null || guard) return array[0];
    return _.initial(array, array.length - n);
  }; // Returns everything but the last entry of the array. Especially useful on
  // the arguments object. Passing **n** will return all the values in
  // the array, excluding the last N.


  _.initial = function (array, n, guard) {
    return slice.call(array, 0, Math.max(0, array.length - (n == null || guard ? 1 : n)));
  }; // Get the last element of an array. Passing **n** will return the last N
  // values in the array.


  _.last = function (array, n, guard) {
    if (array == null) return void 0;
    if (n == null || guard) return array[array.length - 1];
    return _.rest(array, Math.max(0, array.length - n));
  }; // Returns everything but the first entry of the array. Aliased as `tail` and `drop`.
  // Especially useful on the arguments object. Passing an **n** will return
  // the rest N values in the array.


  _.rest = _.tail = _.drop = function (array, n, guard) {
    return slice.call(array, n == null || guard ? 1 : n);
  }; // Trim out all falsy values from an array.


  _.compact = function (array) {
    return _.filter(array, _.identity);
  }; // Internal implementation of a recursive `flatten` function.


  var flatten = function (input, shallow, strict, startIndex) {
    var output = [],
        idx = 0;

    for (var i = startIndex || 0, length = input && input.length; i < length; i++) {
      var value = input[i];

      if (isArrayLike(value) && (_.isArray(value) || _.isArguments(value))) {
        //flatten current level of array or arguments object
        if (!shallow) value = flatten(value, shallow, strict);
        var j = 0,
            len = value.length;
        output.length += len;

        while (j < len) {
          output[idx++] = value[j++];
        }
      } else if (!strict) {
        output[idx++] = value;
      }
    }

    return output;
  }; // Flatten out an array, either recursively (by default), or just one level.


  _.flatten = function (array, shallow) {
    return flatten(array, shallow, false);
  }; // Return a version of the array that does not contain the specified value(s).


  _.without = function (array) {
    return _.difference(array, slice.call(arguments, 1));
  }; // Produce a duplicate-free version of the array. If the array has already
  // been sorted, you have the option of using a faster algorithm.
  // Aliased as `unique`.


  _.uniq = _.unique = function (array, isSorted, iteratee, context) {
    if (array == null) return [];

    if (!_.isBoolean(isSorted)) {
      context = iteratee;
      iteratee = isSorted;
      isSorted = false;
    }

    if (iteratee != null) iteratee = cb(iteratee, context);
    var result = [];
    var seen = [];

    for (var i = 0, length = array.length; i < length; i++) {
      var value = array[i],
          computed = iteratee ? iteratee(value, i, array) : value;

      if (isSorted) {
        if (!i || seen !== computed) result.push(value);
        seen = computed;
      } else if (iteratee) {
        if (!_.contains(seen, computed)) {
          seen.push(computed);
          result.push(value);
        }
      } else if (!_.contains(result, value)) {
        result.push(value);
      }
    }

    return result;
  }; // Produce an array that contains the union: each distinct element from all of
  // the passed-in arrays.


  _.union = function () {
    return _.uniq(flatten(arguments, true, true));
  }; // Produce an array that contains every item shared between all the
  // passed-in arrays.


  _.intersection = function (array) {
    if (array == null) return [];
    var result = [];
    var argsLength = arguments.length;

    for (var i = 0, length = array.length; i < length; i++) {
      var item = array[i];
      if (_.contains(result, item)) continue;

      for (var j = 1; j < argsLength; j++) {
        if (!_.contains(arguments[j], item)) break;
      }

      if (j === argsLength) result.push(item);
    }

    return result;
  }; // Take the difference between one array and a number of other arrays.
  // Only the elements present in just the first array will remain.


  _.difference = function (array) {
    var rest = flatten(arguments, true, true, 1);
    return _.filter(array, function (value) {
      return !_.contains(rest, value);
    });
  }; // Zip together multiple lists into a single array -- elements that share
  // an index go together.


  _.zip = function () {
    return _.unzip(arguments);
  }; // Complement of _.zip. Unzip accepts an array of arrays and groups
  // each array's elements on shared indices


  _.unzip = function (array) {
    var length = array && _.max(array, 'length').length || 0;
    var result = Array(length);

    for (var index = 0; index < length; index++) {
      result[index] = _.pluck(array, index);
    }

    return result;
  }; // Converts lists into objects. Pass either a single array of `[key, value]`
  // pairs, or two parallel arrays of the same length -- one of keys, and one of
  // the corresponding values.


  _.object = function (list, values) {
    var result = {};

    for (var i = 0, length = list && list.length; i < length; i++) {
      if (values) {
        result[list[i]] = values[i];
      } else {
        result[list[i][0]] = list[i][1];
      }
    }

    return result;
  }; // Return the position of the first occurrence of an item in an array,
  // or -1 if the item is not included in the array.
  // If the array is large and already in sort order, pass `true`
  // for **isSorted** to use binary search.


  _.indexOf = function (array, item, isSorted) {
    var i = 0,
        length = array && array.length;

    if (typeof isSorted == 'number') {
      i = isSorted < 0 ? Math.max(0, length + isSorted) : isSorted;
    } else if (isSorted && length) {
      i = _.sortedIndex(array, item);
      return array[i] === item ? i : -1;
    }

    if (item !== item) {
      return _.findIndex(slice.call(array, i), _.isNaN);
    }

    for (; i < length; i++) if (array[i] === item) return i;

    return -1;
  };

  _.lastIndexOf = function (array, item, from) {
    var idx = array ? array.length : 0;

    if (typeof from == 'number') {
      idx = from < 0 ? idx + from + 1 : Math.min(idx, from + 1);
    }

    if (item !== item) {
      return _.findLastIndex(slice.call(array, 0, idx), _.isNaN);
    }

    while (--idx >= 0) if (array[idx] === item) return idx;

    return -1;
  }; // Generator function to create the findIndex and findLastIndex functions


  function createIndexFinder(dir) {
    return function (array, predicate, context) {
      predicate = cb(predicate, context);
      var length = array != null && array.length;
      var index = dir > 0 ? 0 : length - 1;

      for (; index >= 0 && index < length; index += dir) {
        if (predicate(array[index], index, array)) return index;
      }

      return -1;
    };
  } // Returns the first index on an array-like that passes a predicate test


  _.findIndex = createIndexFinder(1);
  _.findLastIndex = createIndexFinder(-1); // Use a comparator function to figure out the smallest index at which
  // an object should be inserted so as to maintain order. Uses binary search.

  _.sortedIndex = function (array, obj, iteratee, context) {
    iteratee = cb(iteratee, context, 1);
    var value = iteratee(obj);
    var low = 0,
        high = array.length;

    while (low < high) {
      var mid = Math.floor((low + high) / 2);
      if (iteratee(array[mid]) < value) low = mid + 1;else high = mid;
    }

    return low;
  }; // Generate an integer Array containing an arithmetic progression. A port of
  // the native Python `range()` function. See
  // [the Python documentation](http://docs.python.org/library/functions.html#range).


  _.range = function (start, stop, step) {
    if (arguments.length <= 1) {
      stop = start || 0;
      start = 0;
    }

    step = step || 1;
    var length = Math.max(Math.ceil((stop - start) / step), 0);
    var range = Array(length);

    for (var idx = 0; idx < length; idx++, start += step) {
      range[idx] = start;
    }

    return range;
  }; // Function (ahem) Functions
  // ------------------
  // Determines whether to execute a function as a constructor
  // or a normal function with the provided arguments


  var executeBound = function (sourceFunc, boundFunc, context, callingContext, args) {
    if (!(callingContext instanceof boundFunc)) return sourceFunc.apply(context, args);
    var self = baseCreate(sourceFunc.prototype);
    var result = sourceFunc.apply(self, args);
    if (_.isObject(result)) return result;
    return self;
  }; // Create a function bound to a given object (assigning `this`, and arguments,
  // optionally). Delegates to **ECMAScript 5**'s native `Function.bind` if
  // available.


  _.bind = function (func, context) {
    if (nativeBind && func.bind === nativeBind) return nativeBind.apply(func, slice.call(arguments, 1));
    if (!_.isFunction(func)) throw new TypeError('Bind must be called on a function');
    var args = slice.call(arguments, 2);

    var bound = function () {
      return executeBound(func, bound, context, this, args.concat(slice.call(arguments)));
    };

    return bound;
  }; // Partially apply a function by creating a version that has had some of its
  // arguments pre-filled, without changing its dynamic `this` context. _ acts
  // as a placeholder, allowing any combination of arguments to be pre-filled.


  _.partial = function (func) {
    var boundArgs = slice.call(arguments, 1);

    var bound = function () {
      var position = 0,
          length = boundArgs.length;
      var args = Array(length);

      for (var i = 0; i < length; i++) {
        args[i] = boundArgs[i] === _ ? arguments[position++] : boundArgs[i];
      }

      while (position < arguments.length) args.push(arguments[position++]);

      return executeBound(func, bound, this, this, args);
    };

    return bound;
  }; // Bind a number of an object's methods to that object. Remaining arguments
  // are the method names to be bound. Useful for ensuring that all callbacks
  // defined on an object belong to it.


  _.bindAll = function (obj) {
    var i,
        length = arguments.length,
        key;
    if (length <= 1) throw new Error('bindAll must be passed function names');

    for (i = 1; i < length; i++) {
      key = arguments[i];
      obj[key] = _.bind(obj[key], obj);
    }

    return obj;
  }; // Memoize an expensive function by storing its results.


  _.memoize = function (func, hasher) {
    var memoize = function (key) {
      var cache = memoize.cache;
      var address = '' + (hasher ? hasher.apply(this, arguments) : key);
      if (!_.has(cache, address)) cache[address] = func.apply(this, arguments);
      return cache[address];
    };

    memoize.cache = {};
    return memoize;
  }; // Delays a function for the given number of milliseconds, and then calls
  // it with the arguments supplied.


  _.delay = function (func, wait) {
    var args = slice.call(arguments, 2);
    return setTimeout(function () {
      return func.apply(null, args);
    }, wait);
  }; // Defers a function, scheduling it to run after the current call stack has
  // cleared.


  _.defer = _.partial(_.delay, _, 1); // Returns a function, that, when invoked, will only be triggered at most once
  // during a given window of time. Normally, the throttled function will run
  // as much as it can, without ever going more than once per `wait` duration;
  // but if you'd like to disable the execution on the leading edge, pass
  // `{leading: false}`. To disable execution on the trailing edge, ditto.

  _.throttle = function (func, wait, options) {
    var context, args, result;
    var timeout = null;
    var previous = 0;
    if (!options) options = {};

    var later = function () {
      previous = options.leading === false ? 0 : _.now();
      timeout = null;
      result = func.apply(context, args);
      if (!timeout) context = args = null;
    };

    return function () {
      var now = _.now();

      if (!previous && options.leading === false) previous = now;
      var remaining = wait - (now - previous);
      context = this;
      args = arguments;

      if (remaining <= 0 || remaining > wait) {
        if (timeout) {
          clearTimeout(timeout);
          timeout = null;
        }

        previous = now;
        result = func.apply(context, args);
        if (!timeout) context = args = null;
      } else if (!timeout && options.trailing !== false) {
        timeout = setTimeout(later, remaining);
      }

      return result;
    };
  }; // Returns a function, that, as long as it continues to be invoked, will not
  // be triggered. The function will be called after it stops being called for
  // N milliseconds. If `immediate` is passed, trigger the function on the
  // leading edge, instead of the trailing.


  _.debounce = function (func, wait, immediate) {
    var timeout, args, context, timestamp, result;

    var later = function () {
      var last = _.now() - timestamp;

      if (last < wait && last >= 0) {
        timeout = setTimeout(later, wait - last);
      } else {
        timeout = null;

        if (!immediate) {
          result = func.apply(context, args);
          if (!timeout) context = args = null;
        }
      }
    };

    return function () {
      context = this;
      args = arguments;
      timestamp = _.now();
      var callNow = immediate && !timeout;
      if (!timeout) timeout = setTimeout(later, wait);

      if (callNow) {
        result = func.apply(context, args);
        context = args = null;
      }

      return result;
    };
  }; // Returns the first function passed as an argument to the second,
  // allowing you to adjust arguments, run code before and after, and
  // conditionally execute the original function.


  _.wrap = function (func, wrapper) {
    return _.partial(wrapper, func);
  }; // Returns a negated version of the passed-in predicate.


  _.negate = function (predicate) {
    return function () {
      return !predicate.apply(this, arguments);
    };
  }; // Returns a function that is the composition of a list of functions, each
  // consuming the return value of the function that follows.


  _.compose = function () {
    var args = arguments;
    var start = args.length - 1;
    return function () {
      var i = start;
      var result = args[start].apply(this, arguments);

      while (i--) result = args[i].call(this, result);

      return result;
    };
  }; // Returns a function that will only be executed on and after the Nth call.


  _.after = function (times, func) {
    return function () {
      if (--times < 1) {
        return func.apply(this, arguments);
      }
    };
  }; // Returns a function that will only be executed up to (but not including) the Nth call.


  _.before = function (times, func) {
    var memo;
    return function () {
      if (--times > 0) {
        memo = func.apply(this, arguments);
      }

      if (times <= 1) func = null;
      return memo;
    };
  }; // Returns a function that will be executed at most one time, no matter how
  // often you call it. Useful for lazy initialization.


  _.once = _.partial(_.before, 2); // Object Functions
  // ----------------
  // Keys in IE < 9 that won't be iterated by `for key in ...` and thus missed.

  var hasEnumBug = !{
    toString: null
  }.propertyIsEnumerable('toString');
  var nonEnumerableProps = ['valueOf', 'isPrototypeOf', 'toString', 'propertyIsEnumerable', 'hasOwnProperty', 'toLocaleString'];

  function collectNonEnumProps(obj, keys) {
    var nonEnumIdx = nonEnumerableProps.length;
    var constructor = obj.constructor;
    var proto = _.isFunction(constructor) && constructor.prototype || ObjProto; // Constructor is a special case.

    var prop = 'constructor';
    if (_.has(obj, prop) && !_.contains(keys, prop)) keys.push(prop);

    while (nonEnumIdx--) {
      prop = nonEnumerableProps[nonEnumIdx];

      if (prop in obj && obj[prop] !== proto[prop] && !_.contains(keys, prop)) {
        keys.push(prop);
      }
    }
  } // Retrieve the names of an object's own properties.
  // Delegates to **ECMAScript 5**'s native `Object.keys`


  _.keys = function (obj) {
    if (!_.isObject(obj)) return [];
    if (nativeKeys) return nativeKeys(obj);
    var keys = [];

    for (var key in obj) if (_.has(obj, key)) keys.push(key); // Ahem, IE < 9.


    if (hasEnumBug) collectNonEnumProps(obj, keys);
    return keys;
  }; // Retrieve all the property names of an object.


  _.allKeys = function (obj) {
    if (!_.isObject(obj)) return [];
    var keys = [];

    for (var key in obj) keys.push(key); // Ahem, IE < 9.


    if (hasEnumBug) collectNonEnumProps(obj, keys);
    return keys;
  }; // Retrieve the values of an object's properties.


  _.values = function (obj) {
    var keys = _.keys(obj);

    var length = keys.length;
    var values = Array(length);

    for (var i = 0; i < length; i++) {
      values[i] = obj[keys[i]];
    }

    return values;
  }; // Returns the results of applying the iteratee to each element of the object
  // In contrast to _.map it returns an object


  _.mapObject = function (obj, iteratee, context) {
    iteratee = cb(iteratee, context);

    var keys = _.keys(obj),
        length = keys.length,
        results = {},
        currentKey;

    for (var index = 0; index < length; index++) {
      currentKey = keys[index];
      results[currentKey] = iteratee(obj[currentKey], currentKey, obj);
    }

    return results;
  }; // Convert an object into a list of `[key, value]` pairs.


  _.pairs = function (obj) {
    var keys = _.keys(obj);

    var length = keys.length;
    var pairs = Array(length);

    for (var i = 0; i < length; i++) {
      pairs[i] = [keys[i], obj[keys[i]]];
    }

    return pairs;
  }; // Invert the keys and values of an object. The values must be serializable.


  _.invert = function (obj) {
    var result = {};

    var keys = _.keys(obj);

    for (var i = 0, length = keys.length; i < length; i++) {
      result[obj[keys[i]]] = keys[i];
    }

    return result;
  }; // Return a sorted list of the function names available on the object.
  // Aliased as `methods`


  _.functions = _.methods = function (obj) {
    var names = [];

    for (var key in obj) {
      if (_.isFunction(obj[key])) names.push(key);
    }

    return names.sort();
  }; // Extend a given object with all the properties in passed-in object(s).


  _.extend = createAssigner(_.allKeys); // Assigns a given object with all the own properties in the passed-in object(s)
  // (https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object/assign)

  _.extendOwn = _.assign = createAssigner(_.keys); // Returns the first key on an object that passes a predicate test

  _.findKey = function (obj, predicate, context) {
    predicate = cb(predicate, context);

    var keys = _.keys(obj),
        key;

    for (var i = 0, length = keys.length; i < length; i++) {
      key = keys[i];
      if (predicate(obj[key], key, obj)) return key;
    }
  }; // Return a copy of the object only containing the whitelisted properties.


  _.pick = function (object, oiteratee, context) {
    var result = {},
        obj = object,
        iteratee,
        keys;
    if (obj == null) return result;

    if (_.isFunction(oiteratee)) {
      keys = _.allKeys(obj);
      iteratee = optimizeCb(oiteratee, context);
    } else {
      keys = flatten(arguments, false, false, 1);

      iteratee = function (value, key, obj) {
        return key in obj;
      };

      obj = Object(obj);
    }

    for (var i = 0, length = keys.length; i < length; i++) {
      var key = keys[i];
      var value = obj[key];
      if (iteratee(value, key, obj)) result[key] = value;
    }

    return result;
  }; // Return a copy of the object without the blacklisted properties.


  _.omit = function (obj, iteratee, context) {
    if (_.isFunction(iteratee)) {
      iteratee = _.negate(iteratee);
    } else {
      var keys = _.map(flatten(arguments, false, false, 1), String);

      iteratee = function (value, key) {
        return !_.contains(keys, key);
      };
    }

    return _.pick(obj, iteratee, context);
  }; // Fill in a given object with default properties.


  _.defaults = createAssigner(_.allKeys, true); // Creates an object that inherits from the given prototype object.
  // If additional properties are provided then they will be added to the
  // created object.

  _.create = function (prototype, props) {
    var result = baseCreate(prototype);
    if (props) _.extendOwn(result, props);
    return result;
  }; // Create a (shallow-cloned) duplicate of an object.


  _.clone = function (obj) {
    if (!_.isObject(obj)) return obj;
    return _.isArray(obj) ? obj.slice() : _.extend({}, obj);
  }; // Invokes interceptor with the obj, and then returns obj.
  // The primary purpose of this method is to "tap into" a method chain, in
  // order to perform operations on intermediate results within the chain.


  _.tap = function (obj, interceptor) {
    interceptor(obj);
    return obj;
  }; // Returns whether an object has a given set of `key:value` pairs.


  _.isMatch = function (object, attrs) {
    var keys = _.keys(attrs),
        length = keys.length;

    if (object == null) return !length;
    var obj = Object(object);

    for (var i = 0; i < length; i++) {
      var key = keys[i];
      if (attrs[key] !== obj[key] || !(key in obj)) return false;
    }

    return true;
  }; // Internal recursive comparison function for `isEqual`.


  var eq = function (a, b, aStack, bStack) {
    // Identical objects are equal. `0 === -0`, but they aren't identical.
    // See the [Harmony `egal` proposal](http://wiki.ecmascript.org/doku.php?id=harmony:egal).
    if (a === b) return a !== 0 || 1 / a === 1 / b; // A strict comparison is necessary because `null == undefined`.

    if (a == null || b == null) return a === b; // Unwrap any wrapped objects.

    if (a instanceof _) a = a._wrapped;
    if (b instanceof _) b = b._wrapped; // Compare `[[Class]]` names.

    var className = toString.call(a);
    if (className !== toString.call(b)) return false;

    switch (className) {
      // Strings, numbers, regular expressions, dates, and booleans are compared by value.
      case '[object RegExp]': // RegExps are coerced to strings for comparison (Note: '' + /a/i === '/a/i')

      case '[object String]':
        // Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is
        // equivalent to `new String("5")`.
        return '' + a === '' + b;

      case '[object Number]':
        // `NaN`s are equivalent, but non-reflexive.
        // Object(NaN) is equivalent to NaN
        if (+a !== +a) return +b !== +b; // An `egal` comparison is performed for other numeric values.

        return +a === 0 ? 1 / +a === 1 / b : +a === +b;

      case '[object Date]':
      case '[object Boolean]':
        // Coerce dates and booleans to numeric primitive values. Dates are compared by their
        // millisecond representations. Note that invalid dates with millisecond representations
        // of `NaN` are not equivalent.
        return +a === +b;
    }

    var areArrays = className === '[object Array]';

    if (!areArrays) {
      if (typeof a != 'object' || typeof b != 'object') return false; // Objects with different constructors are not equivalent, but `Object`s or `Array`s
      // from different frames are.

      var aCtor = a.constructor,
          bCtor = b.constructor;

      if (aCtor !== bCtor && !(_.isFunction(aCtor) && aCtor instanceof aCtor && _.isFunction(bCtor) && bCtor instanceof bCtor) && 'constructor' in a && 'constructor' in b) {
        return false;
      }
    } // Assume equality for cyclic structures. The algorithm for detecting cyclic
    // structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`.
    // Initializing stack of traversed objects.
    // It's done here since we only need them for objects and arrays comparison.


    aStack = aStack || [];
    bStack = bStack || [];
    var length = aStack.length;

    while (length--) {
      // Linear search. Performance is inversely proportional to the number of
      // unique nested structures.
      if (aStack[length] === a) return bStack[length] === b;
    } // Add the first object to the stack of traversed objects.


    aStack.push(a);
    bStack.push(b); // Recursively compare objects and arrays.

    if (areArrays) {
      // Compare array lengths to determine if a deep comparison is necessary.
      length = a.length;
      if (length !== b.length) return false; // Deep compare the contents, ignoring non-numeric properties.

      while (length--) {
        if (!eq(a[length], b[length], aStack, bStack)) return false;
      }
    } else {
      // Deep compare objects.
      var keys = _.keys(a),
          key;

      length = keys.length; // Ensure that both objects contain the same number of properties before comparing deep equality.

      if (_.keys(b).length !== length) return false;

      while (length--) {
        // Deep compare each member
        key = keys[length];
        if (!(_.has(b, key) && eq(a[key], b[key], aStack, bStack))) return false;
      }
    } // Remove the first object from the stack of traversed objects.


    aStack.pop();
    bStack.pop();
    return true;
  }; // Perform a deep comparison to check if two objects are equal.


  _.isEqual = function (a, b) {
    return eq(a, b);
  }; // Is a given array, string, or object empty?
  // An "empty" object has no enumerable own-properties.


  _.isEmpty = function (obj) {
    if (obj == null) return true;
    if (isArrayLike(obj) && (_.isArray(obj) || _.isString(obj) || _.isArguments(obj))) return obj.length === 0;
    return _.keys(obj).length === 0;
  }; // Is a given value a DOM element?


  _.isElement = function (obj) {
    return !!(obj && obj.nodeType === 1);
  }; // Is a given value an array?
  // Delegates to ECMA5's native Array.isArray


  _.isArray = nativeIsArray || function (obj) {
    return toString.call(obj) === '[object Array]';
  }; // Is a given variable an object?


  _.isObject = function (obj) {
    var type = typeof obj;
    return type === 'function' || type === 'object' && !!obj;
  }; // Add some isType methods: isArguments, isFunction, isString, isNumber, isDate, isRegExp, isError.


  _.each(['Arguments', 'Function', 'String', 'Number', 'Date', 'RegExp', 'Error'], function (name) {
    _['is' + name] = function (obj) {
      return toString.call(obj) === '[object ' + name + ']';
    };
  }); // Define a fallback version of the method in browsers (ahem, IE < 9), where
  // there isn't any inspectable "Arguments" type.


  if (!_.isArguments(arguments)) {
    _.isArguments = function (obj) {
      return _.has(obj, 'callee');
    };
  } // Optimize `isFunction` if appropriate. Work around some typeof bugs in old v8,
  // IE 11 (#1621), and in Safari 8 (#1929).


  if (typeof /./ != 'function' && typeof Int8Array != 'object') {
    _.isFunction = function (obj) {
      return typeof obj == 'function' || false;
    };
  } // Is a given object a finite number?


  _.isFinite = function (obj) {
    return isFinite(obj) && !isNaN(parseFloat(obj));
  }; // Is the given value `NaN`? (NaN is the only number which does not equal itself).


  _.isNaN = function (obj) {
    return _.isNumber(obj) && obj !== +obj;
  }; // Is a given value a boolean?


  _.isBoolean = function (obj) {
    return obj === true || obj === false || toString.call(obj) === '[object Boolean]';
  }; // Is a given value equal to null?


  _.isNull = function (obj) {
    return obj === null;
  }; // Is a given variable undefined?


  _.isUndefined = function (obj) {
    return obj === void 0;
  }; // Shortcut function for checking if an object has a given property directly
  // on itself (in other words, not on a prototype).


  _.has = function (obj, key) {
    return obj != null && hasOwnProperty.call(obj, key);
  }; // Utility Functions
  // -----------------
  // Run Underscore.js in *noConflict* mode, returning the `_` variable to its
  // previous owner. Returns a reference to the Underscore object.


  _.noConflict = function () {
    root._ = previousUnderscore;
    return this;
  }; // Keep the identity function around for default iteratees.


  _.identity = function (value) {
    return value;
  }; // Predicate-generating functions. Often useful outside of Underscore.


  _.constant = function (value) {
    return function () {
      return value;
    };
  };

  _.noop = function () {};

  _.property = function (key) {
    return function (obj) {
      return obj == null ? void 0 : obj[key];
    };
  }; // Generates a function for a given object that returns a given property.


  _.propertyOf = function (obj) {
    return obj == null ? function () {} : function (key) {
      return obj[key];
    };
  }; // Returns a predicate for checking whether an object has a given set of 
  // `key:value` pairs.


  _.matcher = _.matches = function (attrs) {
    attrs = _.extendOwn({}, attrs);
    return function (obj) {
      return _.isMatch(obj, attrs);
    };
  }; // Run a function **n** times.


  _.times = function (n, iteratee, context) {
    var accum = Array(Math.max(0, n));
    iteratee = optimizeCb(iteratee, context, 1);

    for (var i = 0; i < n; i++) accum[i] = iteratee(i);

    return accum;
  }; // Return a random integer between min and max (inclusive).


  _.random = function (min, max) {
    if (max == null) {
      max = min;
      min = 0;
    }

    return min + Math.floor(Math.random() * (max - min + 1));
  }; // A (possibly faster) way to get the current timestamp as an integer.


  _.now = Date.now || function () {
    return new Date().getTime();
  }; // List of HTML entities for escaping.


  var escapeMap = {
    '&': '&amp;',
    '<': '&lt;',
    '>': '&gt;',
    '"': '&quot;',
    "'": '&#x27;',
    '`': '&#x60;'
  };

  var unescapeMap = _.invert(escapeMap); // Functions for escaping and unescaping strings to/from HTML interpolation.


  var createEscaper = function (map) {
    var escaper = function (match) {
      return map[match];
    }; // Regexes for identifying a key that needs to be escaped


    var source = '(?:' + _.keys(map).join('|') + ')';
    var testRegexp = RegExp(source);
    var replaceRegexp = RegExp(source, 'g');
    return function (string) {
      string = string == null ? '' : '' + string;
      return testRegexp.test(string) ? string.replace(replaceRegexp, escaper) : string;
    };
  };

  _.escape = createEscaper(escapeMap);
  _.unescape = createEscaper(unescapeMap); // If the value of the named `property` is a function then invoke it with the
  // `object` as context; otherwise, return it.

  _.result = function (object, property, fallback) {
    var value = object == null ? void 0 : object[property];

    if (value === void 0) {
      value = fallback;
    }

    return _.isFunction(value) ? value.call(object) : value;
  }; // Generate a unique integer id (unique within the entire client session).
  // Useful for temporary DOM ids.


  var idCounter = 0;

  _.uniqueId = function (prefix) {
    var id = ++idCounter + '';
    return prefix ? prefix + id : id;
  }; // By default, Underscore uses ERB-style template delimiters, change the
  // following template settings to use alternative delimiters.


  _.templateSettings = {
    evaluate: /<%([\s\S]+?)%>/g,
    interpolate: /<%=([\s\S]+?)%>/g,
    escape: /<%-([\s\S]+?)%>/g
  }; // When customizing `templateSettings`, if you don't want to define an
  // interpolation, evaluation or escaping regex, we need one that is
  // guaranteed not to match.

  var noMatch = /(.)^/; // Certain characters need to be escaped so that they can be put into a
  // string literal.

  var escapes = {
    "'": "'",
    '\\': '\\',
    '\r': 'r',
    '\n': 'n',
    '\u2028': 'u2028',
    '\u2029': 'u2029'
  };
  var escaper = /\\|'|\r|\n|\u2028|\u2029/g;

  var escapeChar = function (match) {
    return '\\' + escapes[match];
  }; // JavaScript micro-templating, similar to John Resig's implementation.
  // Underscore templating handles arbitrary delimiters, preserves whitespace,
  // and correctly escapes quotes within interpolated code.
  // NB: `oldSettings` only exists for backwards compatibility.


  _.template = function (text, settings, oldSettings) {
    if (!settings && oldSettings) settings = oldSettings;
    settings = _.defaults({}, settings, _.templateSettings); // Combine delimiters into one regular expression via alternation.

    var matcher = RegExp([(settings.escape || noMatch).source, (settings.interpolate || noMatch).source, (settings.evaluate || noMatch).source].join('|') + '|$', 'g'); // Compile the template source, escaping string literals appropriately.

    var index = 0;
    var source = "__p+='";
    text.replace(matcher, function (match, escape, interpolate, evaluate, offset) {
      source += text.slice(index, offset).replace(escaper, escapeChar);
      index = offset + match.length;

      if (escape) {
        source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'";
      } else if (interpolate) {
        source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'";
      } else if (evaluate) {
        source += "';\n" + evaluate + "\n__p+='";
      } // Adobe VMs need the match returned to produce the correct offest.


      return match;
    });
    source += "';\n"; // If a variable is not specified, place data values in local scope.

    if (!settings.variable) source = 'with(obj||{}){\n' + source + '}\n';
    source = "var __t,__p='',__j=Array.prototype.join," + "print=function(){__p+=__j.call(arguments,'');};\n" + source + 'return __p;\n';

    try {
      var render = new Function(settings.variable || 'obj', '_', source);
    } catch (e) {
      e.source = source;
      throw e;
    }

    var template = function (data) {
      return render.call(this, data, _);
    }; // Provide the compiled source as a convenience for precompilation.


    var argument = settings.variable || 'obj';
    template.source = 'function(' + argument + '){\n' + source + '}';
    return template;
  }; // Add a "chain" function. Start chaining a wrapped Underscore object.


  _.chain = function (obj) {
    var instance = _(obj);

    instance._chain = true;
    return instance;
  }; // OOP
  // ---------------
  // If Underscore is called as a function, it returns a wrapped object that
  // can be used OO-style. This wrapper holds altered versions of all the
  // underscore functions. Wrapped objects may be chained.
  // Helper function to continue chaining intermediate results.


  var result = function (instance, obj) {
    return instance._chain ? _(obj).chain() : obj;
  }; // Add your own custom functions to the Underscore object.


  _.mixin = function (obj) {
    _.each(_.functions(obj), function (name) {
      var func = _[name] = obj[name];

      _.prototype[name] = function () {
        var args = [this._wrapped];
        push.apply(args, arguments);
        return result(this, func.apply(_, args));
      };
    });
  }; // Add all of the Underscore functions to the wrapper object.


  _.mixin(_); // Add all mutator Array functions to the wrapper.


  _.each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function (name) {
    var method = ArrayProto[name];

    _.prototype[name] = function () {
      var obj = this._wrapped;
      method.apply(obj, arguments);
      if ((name === 'shift' || name === 'splice') && obj.length === 0) delete obj[0];
      return result(this, obj);
    };
  }); // Add all accessor Array functions to the wrapper.


  _.each(['concat', 'join', 'slice'], function (name) {
    var method = ArrayProto[name];

    _.prototype[name] = function () {
      return result(this, method.apply(this._wrapped, arguments));
    };
  }); // Extracts the result from a wrapped and chained object.


  _.prototype.value = function () {
    return this._wrapped;
  }; // Provide unwrapping proxy for some methods used in engine operations
  // such as arithmetic and JSON stringification.


  _.prototype.valueOf = _.prototype.toJSON = _.prototype.value;

  _.prototype.toString = function () {
    return '' + this._wrapped;
  }; // AMD registration happens at the end for compatibility with AMD loaders
  // that may not enforce next-turn semantics on modules. Even though general
  // practice for AMD registration is to be anonymous, underscore registers
  // as a named module because, like jQuery, it is a base library that is
  // popular enough to be bundled in a third party lib, but not be part of
  // an AMD load request. Those cases could generate an error when an
  // anonymous define() is called outside of a loader request.
  //   if (typeof define === 'function' && define.amd) {
  //     define('underscore', [], function() {
  //       return _;
  //     });
  //   }

}).call(this);